Geodetic Engineering: Lecture 3 - Map Design Process

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Questions and Answers

What is a characteristic of direct contact positives?

Drawing placed face-up on printing paper sensitized with light sensitive diazo compounds

What is a disadvantage of direct contact negatives?

Subject to distortion due to exposure to sunlight or special lights

What is a key feature of photocopying process?

Obtains inexpensive copies of prepared map manuscripts

What is the main difference between direct contact positives and negatives?

Presence of distortion in the final print Signup and view all the answers

Which process involves laying the map manuscript next to iron sensitized paper?

Direct contact negatives Signup and view all the answers

What is the impact of using caustic soda in the alteration process on blueprints?

Produces white lines on the prints Signup and view all the answers

What is stenciling in cartography?

A method of duplicating maps using a stencil sheet Signup and view all the answers

How are drawings and details added to a stencil in stenciling?

By cutting with a stylus or typewriter keys Signup and view all the answers

What is the purpose of the wax coating on the stencil sheet in stenciling?

To protect the stencil during cutting Signup and view all the answers

What is direct contact positive in map design?

A process that produces black on white images Signup and view all the answers

How does xerography work in map reproduction?

By using electrostatic charges and toner powder Signup and view all the answers

What is the role of micrographics in map reproduction?

Producing maps on microfilm for storage Signup and view all the answers

What is the biggest drawback of micrographics?

Inability to reproduce solid black areas Signup and view all the answers

Which company developed xerography?

Xerox Corporation Signup and view all the answers

What is the purpose of microfilm in map design?

Reducing storage space needed for maps Signup and view all the answers

What type of company is Xerox in relation to the duplication systems?

A leading company Signup and view all the answers

How does xerography differ from micrographics in terms of chemical involvement?

Micrographics involves chemical solutions, xerography does not Signup and view all the answers

What is the primary benefit of micrographics for map manuscripts?

Efficient record keeping and protection from wear and tear Signup and view all the answers

What is the main difference between the photocopy process and the film photograph process?

Photocopy process exposes the original drawing through a lens directly to sensitized paper, while film photograph process uses a camera to make an exposure on photographic film. Signup and view all the answers

Which process involves using a copy camera for precise enlargement and reductions?

Film photograph process Signup and view all the answers

What is the purpose of xerography in cartography?

To produce high-quality copies on dimensionally stable materials Signup and view all the answers

How does xerography differ from the photocopy process?

Xerography produces quality copies on stable materials, which is different from photocopy. Signup and view all the answers

Which process requires the exposure of the original map or drawing directly on photographic film?

Film photograph process Signup and view all the answers

What is a characteristic feature of a copy camera used in cartography?

It can make precise enlargements and reductions Signup and view all the answers

Study Notes

Map Design Process

Xerography is a successful duplication system developed by Xerox Corporation of America.

Duplication and Reproduction

Micrographics is a dry process that does not involve chemical solutions.
It reduces the space needed for storing maps, making record keeping more efficient and protecting original map manuscripts from wear and tear.
Microfilm is available in rolls, film mounted aperture cards, and microfiche.

Stenciling

Stenciling is an inexpensive duplicating system.
The map is drawn on a stencil sheet with a wax coating on both sides.
Drawings, letterings, and other map details are cut into the stencil by hand with a stylus or by the keys of a typewriter.

Direct Contact Positives

The drawing is placed face-up on printing paper sensitized with light-sensitive diazo compounds and exposed to sunlight or ultraviolet lights.
It is not possible to enlarge or reduce when making direct contact diazo prints.

Direct Contact Negatives

The map manuscript is laid next to iron-sensitized paper and exposed to sunlight or special lights for a specified period.
The exposed sheet is then developed in a bath of water, which can cause some distortion.
A weak solution of caustic soda is used when making alterations on blueprints, and it can be used as an ink to produce white lines.

Photocopy Process

The photocopy process is used to obtain a relatively few inexpensive copies of a prepared map manuscript.
It yields a print in negative form on sensitized paper without the necessity of any intermediate film step.
It involves the exposure of the original drawing on a map through the lens directly to the sensitized paper.

Film Photograph Process

A camera is used to make an exposure of the original map or drawing on photographic film.
Photography for cartography purposes is usually done with a copy camera that can make precise enlargements and reductions and can utilize large sheets of film.
The photographic process produces high-quality copies at desired sizes on dimensionally stable materials, making it suitable for map compilation.